Japan's Osamu Shimomura, now of the Woods Hole Marine Biological Laboratory in Massachusetts, and Americans Martin Chalfie of Columbia University and Roger Tsien of the University of California-San Diego shared the $1.4 million prize for their work on green fluorescent protein, or GFP.
"The remarkable brightly glowing green fluorescent protein, GFP, was first observed in the beautiful jellyfish, Aequorea victoria in 1962," the Nobel Committee for Chemistry said in a statement. "Since then, this protein has become one of the most important tools used in contemporary bioscience."
Shimomura first isolated GFP from jellyfish drifting off the western coast of North America and in 1962 discovered that it glowed bright green under ultraviolet light. For 20 years from 1967, he made a summer pilgrimage to Washington state to gather more than 3,000 jellyfish per day.
Chalfie and colleagues 30 years later got bacteria such as E. coli and tiny worms called C. elegans to produce the protein by splicing in the right gene. The green color of the jellyfish protein appears under blue and ultraviolet light, allowing researchers to illuminate tumor cells, trace toxins and monitor genes as they turn on and off.
Tsien later developed GFP-like proteins that produced a variety of colors so that multiple proteins or cells can be followed simultaneously.
"We can simply look inside an animal and say where has this gene been turned on, when is it turned on and when the protein is made, where does it go?" Chalfie told Reuters in a telephone interview. "They have their own flashlight telling you where they are."
John Frangioni, associate professor of medicine and radiology at Harvard Medical School, told the Associated Press: "This is a technology that has literally transformed medical research. For the first time, scientists could study both genes and proteins in living cells and in living animals."
The award includes the money, a diploma and an invitation to the prize ceremonies in Stockholm and Oslo on Dec. 10.